Heart surgery, particularly the types addressed here (e.g., epicardial electrode placement, atrial ablation) is typically done via either an open approach, or a minimally invasive approach using hand-held rigid endoscopic tools.
Several recent development efforts center around robots intended to perform heart surgery, among other procedures. A commercially available robotic system for cardiac surgery is the da Vinci System available from Intuitive Surgical of Mountain View, Calif. That system is teleoperative, meaning that the motions of the surgeon's hands on input devices are mirrored by laparoscopic manipulators located within the body. While such a system can offer superior dexterity to conventional laparoscopic instruments, it requires some form of stabilization for the heart, requires collapsing a lung, has a limited operative field, and is bulky and expensive.
Closed-chest endoscopic visualization of the epicardium was first described by Santos et al. (Arm Thorac Surg 1977; 23:467-470); subsequent reports have utilized the technique for evaluation of blunt chest trauma, pericardial effusion and lung cancer staging. Lattouf et al have utilized the technique for epicardial implantation of left ventricular pacing leads. In each of these reports, endoscope access required thoracotomy with breach of the left pleural space. Direct access to the pericardial space via subxiphoid puncture is an increasingly practiced technique during catheter ablation procedures. In these reports, once access was achieved, catheter manipulation was guided solely by fluoroscopy. We are aware of cursory attempts at standard pacing lead implantation using this approach which have failed due to inability to achieve fixation.
The challenges of minimally invasive access are further complicated by the goal of avoiding cardiopulmonary bypass, and this goal necessitates surgery on a beating heart. Thus instrumentation is needed that allows stable manipulation of an arbitrary location on the epicardium while the heart is beating. See, for example, published application number 20040172033. Local immobilization of the heart is the approach generally followed with endoscopic stabilizers such as the Endostab device and the endo-Octopus device, which operate with pressure or suction. However, the resulting forces exerted on the myocardium can cause changes in the electrophysiological and hemodynamic performance of the heart, and there has been discussion in the literature regarding the care that must be taken to avoid hemodynamic impairment [Falk, et al., Endoscopic coronary artery bypass grafting on the beating heart using a computer enhanced telemanipulation system. Heart Surg Forum 2:199-205, 1999]. As an alternative, several researchers in robot-assisted endoscopic surgery are investigating active compensation of heartbeat motion by visually tracking the epicardium and moving the tool tips accordingly [avuo{hacek over (g)}lu M C, et al., Robotics for telesurgery: second generation Berkeley/UCSF laparoscopic telesurgical workstation and looking towards the future applications. Industrial Robot 30:22-29, 2003; Ortmaier T J. Motion compensation in minimally invasive robotic surgery. Ph.D. dissertation, Technical University of Munich, Germany, 2003.], but this research problem remains open. The motion of the beating heart is complex. In addition to the challenges of modeling or tracking the heart surface, active compensation will require considerable expense for high-bandwidth actuation to enable manipulation in at least three degrees of freedom over a relatively large workspace (See Cavusoglu, supra).